EMS is built on top of Microsoft PowerShell, a command line shell that allows administrators to perform administrative tasks with simple noun-verb commands called cmdlets. EMS processes commands as instances of .NET classes and objects.
Administrators can use EMS to perform any administrative task normally performed in the Exchange Management Console (EMC) in Exchange 2007 and Exchange 2010, as well as any task typically performed in the Exchange Administration Center (EAC) in Exchange Server 2013. The EMS also allows administrators to complete many tasks not made available through the EMC or EAC.
Microsoft strongly suggests that working knowledge of the EMS is critical for Exchange administrators because it will be Microsoft's preferred administrative tool moving forward.